⬆️ version bump to v4.5

- Update obioptions.Version from "Release 4.4.29" to "/v/ Release v5"
- Update version.txt from 4.29 → .30
(automated by Makefile)

autodoc/docmd/pkg/obiutils/abs_test.md

@@ -0,0 +1,23 @@
+## Semantic Description of `obiutils.Abs` Functionality
+
+The provided Go test suite (`TestAbs`) validates the semantic behavior of a utility function `Abs` from the package [`obiutils`](https://git.metabarcoding.org/obitools/obitools4), part of the OBITools 4 ecosystem — a toolkit for DNA metabarcoding data analysis.
+
+- **Function Purpose**:  
+  `obiutils.Abs` computes the *absolute value* of an integer, returning its non-negative magnitude regardless of sign.
+
+- **Test Coverage**:  
+  The test verifies correctness across two categories:
+    - *Non-negative inputs* (`0`, `1`, `5`, `10`) → outputs unchanged.
+    - *Negative inputs* (`-1`, `-5`, `-10`) → outputs their positive counterparts.
+
+- **Semantic Semantics**:  
+  The function adheres to the mathematical definition: `Abs(x) = x` if `x ≥ 0`, else `-x`.  
+  It ensures robustness for edge cases (e.g., zero) and typical integer ranges used in bioinformatic pipelines.
+
+- **Integration Context**:  
+  As part of `obitools4`, such low-level utilities likely support numerical operations in sequence alignment scoring, quality filtering, or coordinate transformations — where signed differences must be normalized.
+
+- **Test Quality**:  
+  Uses table-driven testing (Go idiom), promoting maintainability and clarity. No external dependencies are required — confirming the function is pure, deterministic, and self-contained.
+
+In summary: `Abs` provides a foundational arithmetic primitive with guaranteed correctness for integer inputs, enabling reliable downstream computation in OBITools’ data processing workflows.